An Indonesia AirAsia A320-200 aircraft has reported a very near miss with a large fire-powered hot-air balloon, with the separation between the two reported at about 10 metres, a hairsbreadth in aviation terms.

The Aviation Herald said the aircraft was performing flight QZ8075 from Yogyakarta to Kuala Namu (Indonesia) and was climbing to about 18,000 feet “when the crew reported a hot-air balloon had just passed their aircraft at about 10 metres/33 feet distance”.

The aircraft continued the climb and landed safely and on schedule in Kuala Namu.

Yogyakarta Air Traffic control reported that three more hot-air balloons had been observed at various altitudes ranging from about 900 feet to 30,000 feet. The balloons, powered by fire, were roughly 10 metres tall and five metres in diameter.

They “obviously were released as result of wish making rituals during festivities at the end of Ramadan,” the Aviation Herald said. Air traffic control warned of such balloons, which can climb up to about 35,000 feet “and disrupt air traffic”.

Two other pilots reported close encounters with the balloons, which were “released into the air as part of Idul Fitri celebrations,” the Jakarta Post reported.

Several pilots have expressed concerns about the balloons, which can be about two storeys tall. An aircraft travelling at speed, several hundred kilometres per hour, would find it hard to avoid a collision if it came upon one suddenly.